Washington: Doubting the "willingness" of Pakistan to go after the militant groups enjoying sanctuary in the country, a top US intelligence official has said these elements have caused major problems for the Afghan and coalition forces working for a "new" Afghanistan.

"We should be cautious in what we anticipate in terms of the ability of our Pakistani partners, and in some cases the willingness to go after the Haqqani network in the Federally Administered Tribal Areas of the Afghan Taliban down in Baluchistan," David Petraeus, Director of CIA, told lawmakers at a Congressional hearing.

Petraeus was responding to a question from Congressman Adam Schiff.

"My chief concern about Afghanistan is the safe haven in Pakistan. And my questions are these. First, do you anticipate any change in the status of the sanctuary that the insurgency finds in Pakistan?" Schiff asked.

"And second, if we can't expect that there's going to be much of a change in that safe haven for the Taliban insurgency, can we reasonably expect that the Afghan forces will be able to defend against an insurgency that enjoys that safe haven once we draw down our troops?" he questioned.

"Finally, should Afghan special forces be allowed to take the fight to the enemy leadership in Pakistan, and the sense of immunity from risk that the senior Taliban leadership enjoy in Pakistan," the Congressman asked.

Petraeus said that there is no question on the existence of safe haven in Pakistan.

"There's no question that there are elements in Pakistan that have enjoyed sanctuary, and that caused major problems for Afghanistan and for the Afghan and coalition forces that are seeking to provide security to enable the development of the new Afghanistan," he said.

Pakistan, he said, has sustained very heavy combat operations against the Tehrik-e-Taliban Pakistani and affiliates, and have tried to squeeze some of these others.

"But again, the thought that they will go in and go after them is probably overly optimistic," Petraeus said.

The prospect of Afghanistan continuing to defend itself from the terrorist in these safe havens, he argued, depends on the amount of assistance that is provided to the Afghan security forces.

"Are there enablers in addition to just, say, money or equipment or various traditional forms of security assistance? We have obviously nearly three years before the end of 2014 to develop that kind of -- what that will consist of, noting again that not just President Obama but the leaders of the other major coalition countries of the NATO forces in Afghanistan have all pledged continued support in varying forms for Afghanistan beyond the end of 2014," he said.

"With respect the Afghan forces should be allowed to go. Well, I think that's obviously a question for Afghanistan, but I think they probably have sufficient fights on their hands without invading the soil of another country, even as significant as is the threat that is posed by some of these safe havens across the border," Petraeus said. (Agencies)